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1.
Nat Methods ; 19(5): 620-627, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35545713

RESUMO

Animal behavior emerges from an interaction between neural network dynamics, musculoskeletal properties and the physical environment. Accessing and understanding the interplay between these elements requires the development of integrative and morphologically realistic neuromechanical simulations. Here we present NeuroMechFly, a data-driven model of the widely studied organism, Drosophila melanogaster. NeuroMechFly combines four independent computational modules: a physics-based simulation environment, a biomechanical exoskeleton, muscle models and neural network controllers. To enable use cases, we first define the minimum degrees of freedom of the leg from real three-dimensional kinematic measurements during walking and grooming. Then, we show how, by replaying these behaviors in the simulator, one can predict otherwise unmeasured torques and contact forces. Finally, we leverage NeuroMechFly's full neuromechanical capacity to discover neural networks and muscle parameters that drive locomotor gaits optimized for speed and stability. Thus, NeuroMechFly can increase our understanding of how behaviors emerge from interactions between complex neuromechanical systems and their physical surroundings.


Assuntos
Drosophila melanogaster , Marcha , Animais , Fenômenos Biomecânicos , Simulação por Computador , Marcha/fisiologia , Modelos Biológicos , Caminhada/fisiologia
2.
Nat Methods ; 18(8): 975-981, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34354294

RESUMO

Markerless three-dimensional (3D) pose estimation has become an indispensable tool for kinematic studies of laboratory animals. Most current methods recover 3D poses by multi-view triangulation of deep network-based two-dimensional (2D) pose estimates. However, triangulation requires multiple synchronized cameras and elaborate calibration protocols that hinder its widespread adoption in laboratory studies. Here we describe LiftPose3D, a deep network-based method that overcomes these barriers by reconstructing 3D poses from a single 2D camera view. We illustrate LiftPose3D's versatility by applying it to multiple experimental systems using flies, mice, rats and macaques, and in circumstances where 3D triangulation is impractical or impossible. Our framework achieves accurate lifting for stereotypical and nonstereotypical behaviors from different camera angles. Thus, LiftPose3D permits high-quality 3D pose estimation in the absence of complex camera arrays and tedious calibration procedures and despite occluded body parts in freely behaving animals.


Assuntos
Algoritmos , Animais de Laboratório/fisiologia , Aprendizado Profundo , Imageamento Tridimensional/métodos , Postura/fisiologia , Animais , Calibragem , Drosophila melanogaster , Feminino , Macaca , Camundongos , Ratos
3.
Rev Panam Salud Publica ; 46: e48, 2022.
Artigo em Espanhol | MEDLINE | ID: mdl-35702715

RESUMO

This paper presents the position of the Latin American working group of the International Foundation for Integrated Care (IFIC). The working group brings together various Latin American actors and organizations in support of actions that facilitate the transformation of health systems in the region towards integrated systems that focus on people not as isolated individuals but as subjects of law in the complex social and environmental contexts where they live and interact. The working group proposes nine pillars of integrated care to be used as a conceptual framework for policy development and changes in practices: 1) shared vision and values; 2) population health; 3) people and communities as partners; 4) resilient communities; 5) capacities of human resources for health; 6) governance and leadership; 7) digital solutions; 8) aligned payment systems; and 9) public transparency. Based on these pillars, lines of work are proposed to strengthen alliances and networks, advocacy, research, and capacity-building, in order to help develop health and social systems that are effectively integrated and focused not only on people but also on communities in Latin America.


Este artigo apresenta o posicionamento do grupo de trabalho latino-americano da Fundação Internacional de Cuidados Integrados (1) (IFIC, na sigla em inglês). A IFIC reúne diversos atores e organizações da América Latina com o fim de apoiar ações que facilitem a transformação dos sistemas de saúde na região para sistemas integrados e centrados nas pessoas, não como indivíduos isolados, mas como sujeitos de direito, nos complexos contextos sociais e ambientais em que vivem e participam. O grupo de trabalho propõe nove pilares de atenção integrada a serem utilizados como marco conceitual na elaboração de políticas e de mudanças nas práticas: 1) visão e valores compartilhados, 2) saúde das populações, 3) pessoas e comunidades como parceiros, 4) comunidades resilientes, 5) capacitação de talento humano em saúde, 6) governança e liderança, 7) soluções digitais, 8) sistemas de pagamento alinhados e 9) transparência perante a população. Com base nesses pilares, são propostas linhas de trabalho nas áreas de fortalecimento de alianças e redes, incidência política, pesquisa e capacitação, que contribuam para materializar na América Latina sistemas sociais e de saúde efetivamente integrados e centrados não só nas pessoas, como também nas comunidades.

4.
Entropy (Basel) ; 24(9)2022 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-36141179

RESUMO

Nature-inspired computing is a promising field of artificial intelligence. This area is mainly devoted to designing computational models based on natural phenomena to address complex problems. Nature provides a rich source of inspiration for designing smart procedures capable of becoming powerful algorithms. Many of these procedures have been successfully developed to treat optimization problems, with impressive results. Nonetheless, for these algorithms to reach their maximum performance, a proper balance between the intensification and the diversification phases is required. The intensification generates a local solution around the best solution by exploiting a promising region. Diversification is responsible for finding new solutions when the main procedure is trapped in a local region. This procedure is usually carryout by non-deterministic fundamentals that do not necessarily provide the expected results. Here, we encounter the stagnation problem, which describes a scenario where the search for the optimum solution stalls before discovering a globally optimal solution. In this work, we propose an efficient technique for detecting and leaving local optimum regions based on Shannon entropy. This component can measure the uncertainty level of the observations taken from random variables. We employ this principle on three well-known population-based bio-inspired optimization algorithms: particle swarm optimization, bat optimization, and black hole algorithm. The proposal's performance is evidenced by solving twenty of the most challenging instances of the multidimensional knapsack problem. Computational results show that the proposed exploration approach is a legitimate alternative to manage the diversification of solutions since the improved techniques can generate a better distribution of the optimal values found. The best results are with the bat method, where in all instances, the enhanced solver with the Shannon exploration strategy works better than its native version. For the other two bio-inspired algorithms, the proposal operates significantly better in over 70% of instances.

5.
Salud Publica Mex ; 60(3): 328-337, 2018.
Artigo em Espanhol | MEDLINE | ID: mdl-29746750

RESUMO

OBJECTIVE: To keep record of the knowledge and use of information of the different food labels on industrialized products in Mexico. MATERIALS AND METHODS: We administered a semi-structured survey-developed by research¬ers free of conflict interestin a subsample of the National Health and Nutrition Survey, 2016. This survey was previously validated and piloted in different populations of varying socio¬economic levels and age and country regions. RESULTS: Data was collected from a total of 8 667 individuals ≥20 years of age. The most frecuent type of label on industrialized foods and beverages was the nutrient table with 41.5% (95%CI 36.9- 46.3) and the least used was the nutrient seal, 4.3% (95%CI 3.1-5.7). CONCLUSIONS: It is of critical importance that the regulating authorities and the Ministry of Health, implement criteria that guarantee the compliance of recommendations promulgated in official documents. As well as the standarization of the percentage of recommended sugar intake based on WHO standards or lower considering the epidemiological alert for diabetes that the country is experiencing.


OBJETIVO: Documentar el conocimiento y uso de la información de las diferentes etiquetas colocadas en los productos industrializados en México. MATERIAL Y MÉTODOS: En una submuestra de la Encuesta Nacional de Salud y Nutrición de Medio Camino 2016, se aplicó un cuestionario semiestructurado, desarrollado por investigadores libres de conflicto de interés, previamente validado y piloteado en población de diferentes estratos socioeconómicos, grupos de edad y regiones del país. RESULTADOS: Se entrevistó a 8 667 adultos ≥20 años de edad. El etiquetado más utilizado para la elección de alimentos y bebidas industrializados fue la "tabla nutrimental" 41.5% (IC95% 36.9-46.3) y el de menor uso el "sello nutrimental" 4.3% (IC95% 3.1-5.7). CONCLUSIONES: Es de suma importancia que las instancias reguladoras, en coordinación con la Secretaría de Salud, implementen un etiquetado frontal rápido de leer y de fácil comprensión con criterios nutrimentales que garanticen el cumplimiento de lo expuesto en los documentos oficiales, así como la estandarización del porcentaje de consumo de azúcar al recomendado por la OMS o a una menor cantidad dada la alerta epidemiológica por diabetes que experimenta el país.


Assuntos
Bebidas , Rotulagem de Alimentos , Alimentos , Adulto , Estudos Transversais , Feminino , Indústria de Processamento de Alimentos , Humanos , Masculino , México , Pessoa de Meia-Idade , Nutrientes , Inquéritos Nutricionais , Adulto Jovem
6.
Environ Sci Technol ; 49(21): 13003-11, 2015 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-26437361

RESUMO

Neonicotinoid residues escaping in vacuum-planter exhaust during maize planting were measured in 25 fields in southwestern Ontario in 2013-2014 using filter bags to collect planter exhaust dust and horizontal and vertical sticky traps to collect planter operation-generated dust. Atrazine residues were used to differentiate between neonicotinoid residues originating from seed or from disturbed soil. Recovery rates of seed-applied neonicotinoids in exhaust were 0.014 and 0.365% in 2013 and 2014, respectively, calculated on the basis of neonicotinoid concentrations in preplant soil and seed application rates. Neonicotinoid exhaust emission rates were 0.0036 and 0.1104 g/ha for 2013 and 2014, respectively, with 99.9472 and 99.7820% originating from treated seed in 2013 and 2014, respectively, calculated on the basis of the atrazine marker. Rates of recovery of seed-applied neonicotinoid residues by exhaust filter bags were 0.015 and 0.437% for 2013 and 2014, respectively. Neonicotinoid residues captured on horizontal and vertical traps were 1.10 ng/cm2 (0.1104 g/ha) and 1.45 ng/cm2 (0.0029 g/ha), respectively, with 92.31 and 93.03% originating from treated seed, respectively, representing 0.3896% of the original active ingredient applied to the seed planted. Exposure to pollinators can be best reduced by strategies to keep active ingredient on the seed, below the soil surface, and in the field where applied.


Assuntos
Anabasina/análise , Inseticidas/análise , Vácuo , Zea mays/crescimento & desenvolvimento , Atrazina/análise , Ontário , Sementes/química , Solo/química
7.
Dev Sci ; 18(5): 832-41, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25438825

RESUMO

The ability to use cognitive emotion regulation strategies such as reappraisal may be a core component of emotional competence across development, but due to methodological challenges in measuring such strategies, they are rarely studied in young children. One neurophysiological measure, the late positive potential (LPP), has been examined in response to reappraisal as a potential neurosignature for emotion regulatory capacity in adults. The association between the LPP and emotion regulatory capacity in children is unknown. The present study examined whether the LPP during reappraisal could predict greater observed adaptive emotion regulation strategy use in school-aged children over a two-year period. Thirty-two 5- to 7-year-olds participated in two identical lab visits spaced two years apart. EEG was continuously recorded during a computerized reappraisal task in which children viewed unpleasant images paired with either reappraisal or negative stories. Next they completed a disappointing and a frustrating task during which emotion regulation strategies were observed. As predicted, children who showed reappraisal-induced reductions in the LPP at the first assessment used significantly more adaptive ER strategies concurrently and two years later. These findings provide observation-based evidence that the LPP may be a viable neurosignature for emotion regulatory capacity in children.


Assuntos
Desenvolvimento Infantil , Cognição/fisiologia , Emoções/fisiologia , Potenciais Evocados/fisiologia , Encéfalo/fisiologia , Criança , Pré-Escolar , Eletroencefalografia , Feminino , Humanos , Estudos Longitudinais , Masculino , Neuropsicologia , Estimulação Luminosa , Estatística como Assunto , Fatores de Tempo
8.
Micromachines (Basel) ; 15(5)2024 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-38793152

RESUMO

Simultaneous interrogation of pump and probe beams interacting in ZnO nanostructures of a two-wave mixing is proposed for dual-path data processing of optical signals by nonlinear optical effects. An enhancement in third-order nonlinear optical properties was exhibited by Al-doped ZnO thin films. Multiphoton absorption and nonlinear refraction were explored by the z-scan technique at 532 nm with nanosecond pulses. The evolution of the optical Kerr effect in the ZnO thin films was analyzed as a function of the incorporation of Al in the sample by a vectorial two-wave mixing method. Electrical and photoconductive effects were evaluated to further characterize the influence of Al in the ZnO solid samples. Potential applications of nonlinear optical parameters for encoding and encrypting information in light can be envisioned.

9.
Environ Entomol ; 2024 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-39037436

RESUMO

Wireworms, the larvae of click beetles (Coleoptera: Elateridae), are often the target of insecticide seed treatments commonly used in corn (Zea mays L.) and soybean (Glycine max (L.) Merr.) production in North America. Nevertheless, there is a lack of knowledge of the species, life history, and economic impact of wireworms present in these agroecosystems. An extensive survey of wireworms was conducted in corn and soybean fields in Ontario, Canada, from 2014 to 2017 to document species distribution and co-occurrence and to identify risk factors related to their abundance. In total, 4,332 specimens were collected from 1,245 different sampling records. The dominant species collected was Limonius agonus (Say) (Coleoptera: Elateridae) comprising 71.5% of the specimens. The remaining wireworm specimens were identified as Hypnoidus abbreviatus (Say), Melanotus similis (Kirby), M. cribulosus (LeConte), M. depressus (Melsheimer), M. communis (Gyllenhal), Agriotes mancus (Say), Aeolus mellillus (Say), and Hemicrepidius spp (Germar). Multiple wireworm species were found to commonly occur within the same field and the same sample. Path analysis was conducted to investigate whether site, soil, and agronomic characteristics influenced wireworm distribution and abundance. Several significant relationships were found between wireworm species and geographic factors, soil texture, and agronomic practices. The results of this survey provide critical information that can be used to improve integrated pest management of the major wireworm genera found in corn and soybean agroecosystems in Ontario.

10.
Braz J Vet Med ; 45: e003123, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38093988

RESUMO

The number of guinea pigs is increasing as pet and their domestication necessitates the study of their pathology and emerging diseases. This study aimed to evaluate guinea pigs' capacity to be infested by Ctenocephalides felis felis fleas, as it is a common parasite among pets that causes irritation, stress, and transmission of other pathogens. Seventeen guinea pigs were infested with C. felis felis. After 48 hours, the animals were combed, and the number of fleas was determined. Guinea pigs had a very low recovery (average of 5%), leading us to conclude that they are not good hosts for this species, despite some literature citing it as an accidental host if infested along with dogs or cats.


Os porquinhos-da-índia como animal de estimação têm aumentado cada vez mais, e, sua domesticação trouxe a necessidade de estudos sobre suas patologias e doenças emergentes. Este estudo teve como objetivo avaliar a capacidade de infestação dos porquinhos-da-índia pela pulga Ctenocephalides felis felis, ectoparasita comum entre os animais domésticos que causa irritação, estresse e transmissão de outros patógenos. Dezessete animais foram infestados com C. felis felis. Após 48 horas, os animais foram penteados e o número de pulgas determinado. Os porquinhos-da-índia tiveram uma recuperação muito baixa (média de 5%), levando-nos a concluir que estes não são bons hospedeiros para essa espécie de pulga, apesar de algumas literaturas os citarem como hospedeiro acidental se conviverem juntamente com cães ou gatos infestados.

11.
Front Plant Sci ; 14: 1286199, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38269134

RESUMO

In flowering plants, after being released from pollen grains, the male gametes use the style channel to migrate towards the ovary where they fertilize awaiting eggs. Environmental pathogens exploit the style passage, resulting in diseased progeny seed. The belief is that pollen also transmits pathogens into the style. By contrast, we hypothesized that pollen carries beneficial microbes that suppress environmental pathogens on the style passage. No prior studies have reported pollen-associated bacterial functions in any plant species. Here, bacteria were cultured from maize (corn) pollen encompassing wild ancestors and farmer-selected landraces from across the Americas, grown in a common field in Canada for one season. In total, 298 bacterial isolates were cultured, spanning 45 genera, 103 species, and 88 OTUs, dominated by Pantoea, Bacillus, Pseudomonas, Erwinia, and Microbacterium. Full-length 16S DNA-based taxonomic profiling showed that 78% of bacterial taxa from the major wild ancestor of maize (Parviglumis teosinte) were present in at least one cultivated landrace. The species names of the bacterial isolates were used to search the pathogen literature systematically; this preliminary evidence predicted that the vast majority of the pollen-associated bacteria analyzed are not maize pathogens. The pollen-associated bacteria were tested in vitro against a style-invading Fusarium pathogen shown to cause Gibberella ear rot (GER): 14 isolates inhibited this pathogen. Genome mining showed that all the anti-Fusarium bacterial species encode phzF, associated with biosynthesis of the natural fungicide, phenazine. To mimic the male gamete migration route, three pollen-associated bacterial strains were sprayed onto styles (silks), followed by Fusarium inoculation; these bacteria reduced GER symptoms and mycotoxin accumulation in progeny seed. Confocal microscopy was used to search for direct evidence that pollen-associated bacteria can defend living silks against Fusarium graminearum (Fg); bacterial strain AS541 (Kluyvera intermedia), isolated from pollen of ancestral Parviglumis, was observed to colonize the susceptible style/silk entry points of Fg (silk epidermis, trichomes, wounds). Furthermore, on style/silk tissue, AS541 colonized/aggregated on Fg hyphae, and was associated with Fg hyphal breaks. These results suggest that pollen has the potential to carry bacteria that can defend the style/silk passage against an environmental pathogen - a novel observation.

12.
Front Plant Sci ; 14: 1292109, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38111882

RESUMO

In flowering plants, fertilization requires exposing maternal style channels to the external environment to capture pollen and transmit its resident sperm nuclei to eggs. This results in progeny seed. However, environmental fungal pathogens invade developing seeds through the style. We hypothesized that prior to environmental exposure, style tissue already possesses bacteria that can protect styles and seed from such pathogens. We further hypothesized that farmers have been inadvertently selecting immature styles over many generations to have such bacteria. We tested these hypotheses in maize, a wind-pollinated crop, which has unusually long styles (silks) that are invaded by the economically-important fungal pathogen Fusarium graminearum (Fg). Here, unpollinated silk-associated bacteria were cultured from a wild teosinte ancestor of maize and diverse maize landraces selected by indigenous farmers across the Americas, grown in a common Canadian field for one season. The bacteria were taxonomically classified using 16S rRNA sequencing. In total, 201 bacteria were cultured, spanning 29 genera, 63 species, and 62 unique OTUs, dominated by Pseudomonas, Pantoea and Microbacterium. These bacteria were tested for their ability to suppress Fg in vitro which identified 10 strains belonging to 6 species: Rouxiella badensis, Pantoea ananatis, Pantoea dispersa, Pseudomonas koreensis, Rahnella aquatilis, and Ewingella americana. Two anti-Fg strains were sprayed onto silks before/after Fg inoculation, resulting in ≤90% reductions in disease (Gibberella ear rot) and 70-100% reductions in associated mycotoxins (deoxynivalenol and zearalenone) in progeny seeds. These strains also protected progeny seeds post-harvest. Confocal fluorescent imaging showed that one silk bacterium (Rouxiella AS112) colonized susceptible entry points of Fg on living silks including stigmatic trichomes, wounds, and epidermal surfaces where they formed thick biofilms. Post-infection, AS112 was associated with masses of dead Fg hyphae. These results suggest that the maize style (silk) is endowed with potent bacteria from the mother plant to protect itself and progeny from Fusarium. The evidence suggests this trait may have been selected by specific indigenous peoples, though this interpretation requires further study.

13.
Pathogens ; 12(11)2023 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-38003787

RESUMO

Styles transmit pollen-derived sperm nuclei from pollen to ovules, but also transmit environmental pathogens. The microbiomes of styles are likely important for reproduction/disease, yet few studies exist. Whether style microbiome compositions are spatially responsive to pathogens is unknown. The maize pathogen Fusarium graminearum enters developing grain through the style (silk). We hypothesized that F. graminearum treatment shifts the cultured transmitting silk microbiome (TSM) compared to healthy silks in a distance-dependent manner. Another objective of the study was to culture microbes for future application. Bacteria were cultured from husk-covered silks of 14 F. graminearum-treated diverse maize genotypes, proximal (tip) and distal (base) to the F. graminearum inoculation site. Long-read 16S sequences from 398 isolates spanned 35 genera, 71 species, and 238 OTUs. More bacteria were cultured from F. graminearum-inoculated tips (271 isolates) versus base (127 isolates); healthy silks were balanced. F. graminearum caused a collapse in diversity of ~20-25% across multiple taxonomic levels. Some species were cultured exclusively or, more often, from F. graminearum-treated silks (e.g., Delftia acidovorans, Klebsiella aerogenes, K. grimontii, Pantoea ananatis, Stenotrophomonas pavanii). Overall, the results suggest that F. graminearum alters the TSM in a distance-dependent manner. Many isolates matched taxa that were previously identified using V4-MiSeq (core and F. graminearum-induced), but long-read sequencing clarified the taxonomy and uncovered greater diversity than was initially predicted (e.g., within Pantoea). These isolates represent the first comprehensive cultured collection from pathogen-treated maize silks to facilitate biocontrol efforts and microbial marker-assisted breeding.

14.
Nat Commun ; 13(1): 5006, 2022 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-36008386

RESUMO

The dynamics and connectivity of neural circuits continuously change on timescales ranging from milliseconds to an animal's lifetime. Therefore, to understand biological networks, minimally invasive methods are required to repeatedly record them in behaving animals. Here we describe a suite of devices that enable long-term optical recordings of the adult Drosophila melanogaster ventral nerve cord (VNC). These consist of transparent, numbered windows to replace thoracic exoskeleton, compliant implants to displace internal organs, a precision arm to assist implantation, and a hinged stage to repeatedly tether flies. To validate and illustrate our toolkit we (i) show minimal impact on animal behavior and survival, (ii) follow the degradation of chordotonal organ mechanosensory nerve terminals over weeks after leg amputation, and (iii) uncover waves of neural activity caffeine ingestion. Thus, our long-term imaging toolkit opens up the investigation of premotor and motor circuit adaptations in response to injury, drug ingestion, aging, learning, and disease.


Assuntos
Proteínas de Drosophila , Drosophila , Animais , Comportamento Animal , Diagnóstico por Imagem , Drosophila/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo
15.
Pest Manag Sci ; 78(8): 3551-3563, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35607861

RESUMO

BACKGROUND: Striacosta albicosta Smith (Lepidoptera: Noctuidae) is a primary pest of corn, Zea mays L., in the Great Lakes region, causing yield loss and exacerbating mycotoxin contamination of grain. Foliar insecticides are currently used to manage S. albicosta; however, the toxicity and residual activity of these insecticides against S. albicosta are unknown. Laboratory and field bioassays were conducted to determine the susceptibility and period of in-field efficacy provided by chlorantraniliprole, lambda-cyhalothrin, spinetoram, and methoxyfenozide against S. albicosta. Bioassay data were used to simulate management scenarios. RESULTS: For all insecticides tested, 1st instars were highly susceptible to the recommended field application rates and were >3-fold more susceptible to insecticides than 3rd instars. Insecticide activity decreased after application for all insecticides, with chlorantraniliprole having the longest residual activity. In simulated management scenarios where an insecticide was applied at or below the recommended 5% egg mass threshold with additional oviposition, methoxyfenozide application resulted in greater larval survival 14 days after application (DAA) than the other insecticides tested. In scenarios where insecticides were applied 7 days before threshold was reached, all insecticides resulted in larval survival. CONCLUSION: These data demonstrate that chlorantraniliprole, lambda-cyhalothrin and spinetoram, applied in conjunction with monitoring, provide effective control of S. albicosta larvae for 10-14 days, whereas methoxyfenozide provides effective control for less than 7 days. © 2022 Society of Chemical Industry.


Assuntos
Inseticidas , Mariposas , Animais , Feminino , Resistência a Inseticidas , Inseticidas/farmacologia , Larva , Ontário , Zea mays
16.
Toxins (Basel) ; 14(7)2022 06 24.
Artigo em Inglês | MEDLINE | ID: mdl-35878169

RESUMO

Mycotoxins are secondary metabolites produced by fungi that, depending on the type and exposure levels, can be a threat to human and animal health. When multiple mycotoxins occur together, their risk effects on human and animal health can be additive or synergistic. Little information is known about the specific types of mycotoxins or their co-occurrence in the state of Michigan and the Great Lakes region of the United States. To understand the types, incidences, severities, and frequency of co-occurrence of mycotoxins in maize grain (Zea mays L.), samples were collected from across Michigan over two years and analyzed for 20 different mycotoxins. Every sample was contaminated with at least four and six mycotoxins in 2017 and 2018, respectively. Incidence and severity of each mycotoxin varied by year and across locations. Correlations were found between mycotoxins, particularly mycotoxins produced by Fusarium spp. Environmental differences at each location played a role in which mycotoxins were present and at what levels. Overall, data from this study demonstrated that mycotoxin co-occurrence occurs at high levels in Michigan, especially with mycotoxins produced by Fusarium spp., such as deoxynivalenol.


Assuntos
Fusarium , Micotoxinas , Animais , Grão Comestível/química , Contaminação de Alimentos/análise , Fusarium/metabolismo , Humanos , Michigan , Micotoxinas/análise , Zea mays/microbiologia
17.
ACS Omega ; 6(3): 1857-1871, 2021 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-33521426

RESUMO

A total of 323 paired grain and grain dust samples (particle size <1650 µm) were collected from combines at harvest (56%), on-farm bins (28%), and experimental minibins seeded with an ochratoxin A (OTA)/Penicillium verrucosum hot spots (15%) of which >98% were soft red winter wheat. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to detect 21 mycotoxins, including deoxynivalenol (DON) and its plant-conjugated form, deoxynivalenol 3-ß-d-glucoside (DON 3-Glc). Except for DON 3-Glc, all mycotoxin concentrations found in grain dust were higher than in grain (p < 0.0030). Pearson correlation coefficients and two-variable regression show a significant (p < 0.0001) linear relationship between the mycotoxin content in grain and that in grain dust with 19 toxins. In only five mycotoxins (DON, OTA, ochratoxin B, citrinin, and enniatin A1), more than 82% of the variation in the data is explained by the two-variable regression model. Because of its higher mean concentration and detection frequency, only DON produced a strong relationship (p < 0.0001, r 2 = 0.949) with low root-mean-square error (RMSE) (293.41 ng/g). The results suggest that modeling levels in grain based upon levels in grain dust can be used to estimate DON in grain bulk.

18.
Sci Rep ; 11(1): 13215, 2021 06 24.
Artigo em Inglês | MEDLINE | ID: mdl-34168223

RESUMO

In corn/maize, silks emerging from cobs capture pollen, and transmit resident sperm nuclei to eggs. There are > 20 million silks per U.S. maize acre. Fungal pathogens invade developing grain using silk channels, including Fusarium graminearum (Fg, temperate environments) and devastating carcinogen-producers (Africa/tropics). Fg contaminates cereal grains with mycotoxins, in particular Deoxynivalenol (DON), known for adverse health effects on humans and livestock. Fitness selection should promote defensive/healthy silks. Here, we report that maize silks, known as styles in other plants, possess complex and dynamic microbiomes at the critical pollen-fungal transmission interval (henceforth: transmitting style microbiome, TSM). Diverse maize genotypes were field-grown in two trial years. MiSeq 16S rRNA gene sequencing of 328 open-pollinated silk samples (healthy/Fg-infected) revealed that the TSM contains > 5000 taxa spanning the prokaryotic tree of life (47 phyla/1300 genera), including nitrogen-fixers. The TSM of silk tip tissue displayed seasonal responsiveness, but possessed a reproducible core of 7-11 MiSeq-amplicon sequence variants (ASVs) dominated by a single Pantoea MiSeq-taxon (15-26% of sequence-counts). Fg-infection collapsed TSM diversity and disturbed predicted metabolic functionality, but doubled overall microbiome size/counts, primarily by elevating 7-25 MiSeq-ASVs, suggestive of a selective microbiome response against infection. This study establishes the maize silk as a model for fundamental/applied research of plant reproductive microbiomes.


Assuntos
Microbiota/genética , Seda/metabolismo , Zea mays/microbiologia , África , Fusarium/genética , Micotoxinas/genética , Pólen/microbiologia , Polinização/fisiologia , RNA Ribossômico 16S/genética
19.
Environ Toxicol Chem ; 39(12): 2420-2423, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33017070

RESUMO

The dispersion of clothianidin from treated seeds was studied in a commercial winter canola field. During planting, using a John Deere 1890 single disk air seeder, a proportion, an estimated 14.2 ± 2.9% (mean ± standard error), of the clothianidin that was applied to the seed escaped into the atmosphere from the seeder's exhaust. We suggest that this source of environmental contamination may be the main contributor that explains the off-target detection of neonicotinoid residues in soils and water near canola plantings better than movement from seed after it is placed in the soil, which is often proposed in the literature. Environ Toxicol Chem 2020;39:2420-2423. © 2020 SETAC.


Assuntos
Brassica napus/crescimento & desenvolvimento , Produção Agrícola/métodos , Poeira/análise , Poluição Ambiental/análise , Guanidinas/análise , Inseticidas/análise , Neonicotinoides/análise , Praguicidas/análise , Tiazóis/análise , Canadá , Sementes/química , Solo/química
20.
J Econ Entomol ; 113(5): 2187-2196, 2020 10 16.
Artigo em Inglês | MEDLINE | ID: mdl-32865199

RESUMO

Fusarium graminearum Schwabe (Hypocreales: Nectriaceae) and Fusarium verticillioides (Saccardo) (Hypocreales: Nectriaceae) Nirenberg infection results in accumulation of deoxynivalenol (DON), zearalenone (ZON), and fumonisin (FBs) mycotoxins in infected corn, Zea mays L. Lepidopteran insect feeding may exacerbate fungal infection by providing entry points on the ear resulting in increased mycotoxin contamination of grain. The objective of the current study was to simulate different types and severity levels (extent of injury) of lepidopteran injury to corn ears at different stages of ear development and its effect on mycotoxin accumulation in grain corn. Field experiments were conducted under conditions favorable for F. graminearum development where insect injury was simulated to corn ears and inoculated with F. graminearum. All simulated injury treatments resulted in elevated mycotoxin concentration compared with ears without simulated injury; however, the severity of injury within a treatment had little effect. Injury to kernels on the side of the ear resulted in greater DON and ZON concentration than injury to tip kernels, grazing injury applied at physiological maturity, or when no injury was simulated. Greater FBs was measured when tip kernel injury was simulated at the blister stage or when side kernel injury was simulated at milk and dent stages compared with noninjured ears, silk clipping, tip injury at milk and dent stages, or grazing injury at physiological maturity. The current study confirms that the risk of mycotoxin accumulation in the Great Lakes region is greater in the presence of ear-feeding insect pests and may differ depending on the feeding behavior of pest species.


Assuntos
Fusarium , Micotoxinas , Animais , Great Lakes Region , Poaceae , Zea mays
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